Their study of the UK’s 165 wind farms shows they are not significantly cleaner, nor cheaper – and they drain the pockets of the consumer and taxpayer. Their gist: wind is unreliable – sometimes it blows, and sometimes it just doesn't. So sometimes wind farms produce a surfeit of electricity, other times next-to-nothing. This means they require a contingency plan – usually, coal-fired power stations kept running in the background, ready to step into the breach at a moment's notice.

Now, the best bit. The CO2 emissions generated by the requisite “stand-by” power-stations aren't counted in the “carbon reduction” totals for wind farms. At best, an oversight; at worst grand hypocrisy – the big industry equivalent of cycling to work whilst a car journeys behind, carrying one's bags.

The background-running of power stations adds to the cost of wind-farmed electricity. Using data from the Royal Academy of Engineering, Booker & North show the cost of a kilowatt hour of electricity from an onshore wind turbine, including the cost of stand-by generation, was 5.4p. The corresponding figure for an offshore turbine is a daunting 7.2p. Gas, nuclear and coal-fuelled power stations can do it for 2.2p, 2.3p and 2.5p respectively.

In a normal world the expense and inefficiency of these wind farms should price them out of the market – but instead it works in their favour. Why? Enter the Government's “Renewables Obligation” scheme, by which energy suppliers are – in effect – forced to buy a certain percentage of their electricity from turbine owners. Suppliers must today purchase some 7.9% of their electricity from renewable sources, rising to 15.4% by 2015.

Which means that wind farms are fast-becoming so many millionaires' playgrounds. Indeed, wind power is the perfect business investment – it will add a splash of green to any bulging portfolio, whilst also raking-in fiscal rewards as surely as any hedge fund or coffee franchise.

While the turbine owners count their profits, the consumers foot the bill via increased energy prices. When Alistair Darling recently banged the table about the 15% rise in bills of N-Power (amongst others) he kept quiet about what they said in return – that about half the increases are directly attributable to the Government's green agenda. It is a boomerang, thrown by the government – and hitting energy consumers smack in the mouth.